Heretofore, uncured or non-crosslinked polyurethanes having hard segments therein such as made from toluene diisocyanate or methylene bispphenyl diisocyanate have had good physical properties However, as the rigidity of the thermoplastic polyurethane elastomer increases, the low temperature toughness becomes poor. Although thermoplastic polyurethane elastomers have been blended with a variety of polymers, blending with carbonyl modified polyolefins for improved low temperature toughness has been unknown since the same are not compatible with polyurethanes. For example, the Handbook of Thermoplastic Elastomers, edited by Benjamin M. Walker, Chapter 5, Thermoplastic Polyurethane Elastomers, page 244, Van Nostrand Reinhold Co., 1979, states that color concentrates in low-density polyethylene can be added to polyurethane. However, the amount of the low density polyethylene is utilized in levels of less than three percent since they effect polymer properties and processing.
Heretofore, carbonyl modified polyolefins have been made and have generally been utilized as coupling agents for glass fiber reinforced polypropylene, as a melt adhesive and as a tie layer for coextrusion of polyolefin with aluminum foil.
U.S. Pat. No. 3,272,890 to O'leary relates to a blend composition containing a very high amount of a polyolefin, for example in excess of 75 percent by weight, and a very low amount of a low hardness polyurethane, for example less than 25 percent by weight.